Expression rule crashes on the Nintex Mobile Form / Javascript workaround does not work

Scenario: I have a form with several panels and dropdown control at the top of the form. Depending of the selection, it will show on of the panels and hide the others. Also, at the top of the form there a checkbox (yes/no) control "show all"...with the default set to false. However, the default value should be true if it is related to an existing item (Id!="") and should be false if it is a new item. To do that, I added the following rule as an expression:

This works perfect on the desktop, but on the mobile I get an error as if I was attempting to use

"Control has one or more invalid line functions"

As the Javascript would be igonored by the Nintex Mobile, I assumed that would be the way to solve the issue. So, I would remove the rule from the control ans try to handle it on the code. However, all my attempts failed misserably.